The overall aim of this project is to characterize the "field effect" of gene methylation in the tumor microenvironment in prostate cancer. We recently discovered that aberrant gene methylation occurs in the stroma and endothelium adjacent to tumor epithelium in prostate cancer patients. This suggests that epigenetic changes such as gene hypermethylation may play a role in the tumor microenvironment. These findings have implications for prostate cancer diagnosis and therpeutic interventions. To pursue these studies, we will conduct an exhaustive examination of promoter methyltion of several genes important in prostate carcinogenesis. Gene methylation profiles in stroma surrounding tumor epitehlium as compared to the tumor itself will be examined.